Examining the noisy life of the college musician: weeklong noise dosimetry of music and non-music activities.

Objective: To examine the contribution of all daily activities, including non-music activities, to the overall noise exposure of college student musicians, and to compare their "noise lives" with those of non-musician college students.

Design: Continuous week-long dosimetry measurements were collected on student musicians and non-musicians. During the measurement period, participants recorded their daily activities in journals.

Understanding speech when wearing communication headsets and hearing protectors with subband processing.

An adaptive, delayless, subband feed-forward control structure is employed to improve the speech signal-to-noise ratio (SNR) in the communication channel of a circumaural headset/hearing protector (HPD) from 90 Hz to 11.3 kHz, and to provide active noise control (ANC) from 50 to 800 Hz to complement the passive attenuation of the HPD. The task involves optimizing the speech SNR for each communication channel subband, subject to limiting the maximum sound level at the ear, maintaining a speech SNR preferred by users, and reducing large inter-band gain differences to improve speech quality.

Attenuation as a function of the canal length of custom-molded earplugs: a pilot study.

Custom-molded earplugs (CMEPs) whose canal segments extend beyond the second bend of the ear canal can provide excellent attenuation but can sometimes be uncomfortable. Attenuation was measured for CMEPs whose canal segments were shortened in 2-mm increments. The within-subjects design permitted illustration of the form of the function relating attenuation to canal segment length for individuals.

Consistency of attenuation across multiple fittings of custom and non-custom earplugs.

Hearing protection devices (HPDs) play a significant role in protecting workers from occupational noise-induced hearing loss. Individual HPD fit-testing estimates the amount of protection, or attenuation, that an individual achieves from a given HPD as it is worn. Results from a single fit-test may not be representative of real-world HPD performance over time, however, due to inconsistency in how the individual fits the HPD from time to time.

Measurements of earplug attenuation under supra-aural and circumaural headphones.

Objective: Supra-aural audiometric headphones are generally not recommended for use in measuring the attenuation of earplugs, because contact between the headphone and pinna and/or earplug could alter the attenuation obtained, and because of concerns of non-comparability between modes of excitation from supra-aural headphones and the sound-field procedure required by the standardized method. In this study, we compared measurements of earplug attenuation obtained under Telephonics TDH-50P supra-aural headphones with measurements obtained under circumaural headphones designed expressly for such testing.

Design: The attenuation of three types of earplugs (foam, premolded quadruple-flange, and custom-molded) was measured in a repeated-measures design.

Evaluation by industrial workers of passive and level-dependent hearing protection devices.

Level-dependent hearing protection devices (HPDs) provide protection from intense sound, while offering amplification for speech and other signals in lower levels of noise. These HPDs have been developed in response to the communication and operational needs of noise-exposed persons in industry and the military. This study was conducted to examine industrial workers' perceptions of the performance of two level-dependent HPDs (one with integrated radio communication capability and one without it) and their customary passive HPDs.

Modeling the Unites States government's economic cost of noise-induced hearing loss for a military population.

Objective: The purpose of this paper is to demonstrate the feasibility and utility of developing economic cost models for noise-induced hearing loss (NIHL). First, we outline an economic model of NIHL for a population of US Navy sailors with an "industrial"-type noise exposure. Next, we describe the effect on NIHL-related cost of varying the two central model inputs--the noise-exposure level and the duration of exposure.

Auditory fitness for duty: a review.

Background: Auditory fitness for duty (AFFD) refers to the possession of hearing abilities sufficient for safe and effective job performance. In jobs such as law enforcement and piloting, where the ability to hear is critical to job performance and safety, hearing loss can decrease performance, even to the point of being hazardous to self and others. Tests of AFFD should provide an employer with a valid assessment of an employee's ability to perform the job safely, without discriminating against the employee purely on the basis of hearing loss.

Enjoyment of music by elderly hearing-impaired listeners.

Background: Anecdotal evidence suggests that hearing loss interferes with the enjoyment of music, although it is not known how widespread this problem currently is.

Purpose: To estimate the prevalence of music-listening difficulties among a group of elderly hearing aid wearers.

Research Design: Interview.

Estimation of equivalent noise exposure level using hearing threshold levels of a population.

Objectives: Noise-induced hearing loss (NIHL) is costly in both human and economic terms. One means of reducing NIHL is to apply engineering controls to hazardous noise sources. To trade off the cost of engineering controls against the total direct monetary costs incurred by NIHL, a means of predicting the amount of NIHL that will be incurred over the life-cycle of a hazardous noise source is necessary.

Perception of roughness by listeners with sensorineural hearing loss.

The perception of auditory roughness presumably results from imperfect spectral or temporal resolution. Sensorineural hearing loss, by affecting spectral resolution, may therefore alter roughness perception. In this study, normal-hearing and hearing-impaired listeners estimated the roughness of amplitude-modulated tones varying in carrier frequency, modulation rate, and modulation depth.

Integration efficiency for speech perception within and across sensory modalities by normal-hearing and hearing-impaired individuals.

In face-to-face speech communication, the listener extracts and integrates information from the acoustic and optic speech signals. Integration occurs within the auditory modality (i.e.

Perception of dissonance by people with normal hearing and sensorineural hearing loss.

The purpose of this study was to determine whether the perceived sensory dissonance of pairs of pure tones (PT dyads) or pairs of harmonic complex tones (HC dyads) is altered due to sensorineural hearing loss. Four normal-hearing (NH) and four hearing-impaired (HI) listeners judged the sensory dissonance of PT dyads geometrically centered at 500 and 2000 Hz, and of HC dyads with fundamental frequencies geometrically centered at 500 Hz. The frequency separation of the members of the dyads varied from 0 Hz to just over an octave.

Speech production in noise with and without hearing protection.

People working in noisy environments often complain of difficulty communicating when they wear hearing protection. It was hypothesized that part of the workers' communication difficulties stem from changes in speech production that occur when hearing protectors are worn. To address this possibility, overall and one-third-octave-band SPL measurements were obtained for 16 men and 16 women as they produced connected speech while wearing foam, flange, or no earplugs (open ears) in quiet and in pink noise at 60, 70, 80, 90, and 100 dB SPL.